Artists' watercolour paints are an important category of artist paints, and are generally used in a traditional manner.
The composition of an artists' modern watercolour paint includes a mixture of microscopic pigment particles which provide the paint colour, and a vehicle that holds the pigment in suspension, allowing it to be applied to a support (paper, board, canvas etc.) with a brush or the like. Once dry the watercolour paint binds to the support. The vehicle consists mostly of a binder which is traditionally, and still most commonly, gum arabic. The vehicle generally also consists of other additives such as a plasticizer to soften the dried gum arabic and help it redissolve, a humectant to help the paint retain moisture, an extender used to thicken the paint without affecting the colour, and water which dissolves or suspends all the ingredients, carries them onto the support and evaporates when its work is done.
In use, traditional watercolour paints are essentially a slurry of pigment particles floating across the support in gum arabic, which has very poor paint binding properties and thus a negative impact on the light fastness of certain pigments which perform well in other paint types such as oil or acrylic paints.
Watercolour paints made with gum arabic as the binder have been in use for hundreds of years and its methodology is still being passed on by todays water-colourists. The re-solubility of dry water colour on paper, and the like, when more wet colour is applied is used as part of the painting technique, and can sometimes be useful. However, since watercolour is a transparent medium and is used in layers, the re-solubility of the first layer and its propensity to dissolve and discolour subsequent layers can be a problem which is difficult to overcome. Expert and adept water colourists are able to very deftly over paint without disturbing the layer underneath, but students or amateur water colourists find this the most difficult thing associated with watercolour painting that they have to learn. Building up layers in a watercolour painting requires very careful hand control and many amateur water colourists find it difficult to control their hand movements precisely.
In research leading up to the present invention the inventor has identified the need for an improved watercolour paint which behaves like a traditional watercolour paint, but is easier to use to achieve multiple layers in a watercolour painting.
Accordingly, an aim, of at least a preferred form of the present invention, is to provide a watercolour paint composition using modern materials which can be formulated to mimic the behaviour of traditional watercolour, but has the advantage of being easier to use to build up layers of a watercolour painting without re-dissolving the under layer(s) or discolouring subsequent layer(s).
One way to prevent a first layer or an under layer from being re-dissolved is to take an acrylic resin based varnish and spray over the under layer or first layer to fix the paint in place on the support. However, the disadvantage of this technique is that a visible film would be produced over the first layer which is not conducive to further layering of the painting.